<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <style>
        h3{
            height: 26px;
            position: relative;
        }
        h3::before{
            content: '';
            width: 4px;
            height: 24px;
            display: block;
            background-color: #84af9b;
            position: absolute;
            top: 1px;
            left: -8px;
        }
    </style>
</head>
<body>
    <!-- 伪元素 ::befor ::after-->
      <h3>热门品牌</h3>
</body>
</html>